The Further Adventures of Li’l Bruce Wayne [The Invincible Super Blog]
Often disregarded as part of any continuity, Li’l Bruce Wayne was a long-running series of light-hearted comic books aimed at children, detailing the life of a young, fantastically wealthy Bruce Wayne (known in the series as “The Happiest Kid On Earth”) in the years before the deaths of Thomas and Martha Wayne and his subsequent transformation into Batman
The series was originally created by Bill Finger and Jerry Robinson to fill a gap in DC’s publishing schedule after the cancellation of More Fun Comics in 1946, and ran through the majority of the Silver Age despite being regarded by editors and fans alike as being “extremely depressing”  and is usually left out of any discussion of the character. It is notable, however, as being the first published comic book work of writer/artist Frank Miller.
Of course, there are covers and details at the link.